Liquid crystal display device and fabrication method thereof

ABSTRACT

A liquid crystal display device has a pixel electrode layer formed between a first data bus line and a second bus line. A first space between the first data bus line and the periphery of the pixel electrode layer is different from a second space between the second data bus line and the periphery of the pixel electrode layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a liquid crystal display (LCD) device and moreparticularly to an LCD device with a non-symmetric design for a spacebetween a data bus line and a pixel electrode in order to effectivelyprevent a disclination effect generated in a liquid crystal reverseregion.

2. Description of the Related Art

Liquid crystal display (LCD) devices are a well-known form of flat paneldisplay with advantages of low power consumption, light weight, thinprofile and low driving voltage. Liquid crystal molecules change theirorientations and photo-electronic effects when an electrical field isapplied. In an LCD display region, an array of pixel regions ispatterned by horizontally extended scanning bus lines and verticallyextended data bus lines. For a TFT-LCD device, each pixel region has athin film transistor (TFT) and a pixel electrode, in which the TFTserves as a switching device. The conventional electrode array designfor a TFT-LCD device, however, has the disadvantage of the so-calledMura phenomenon caused by a disclination effect. The Mura phenomenon isconsidered a push Mura area with light strips which are visible on theLCD screen and detectable in gray scale.

The disclination effect is caused by a strong lateral directionelectrical field between the pixel electrode and the data bus line,resulting in a light leakage area. In order to eliminate thedisclination effect, a transparent insulating film with a thickness of 1μm or more is interposed between the data bus line and the pixelelectrode, and the space between two adjacent pixel electrodes isnarrowed to reach 2˜5 μm to overlap the periphery of the data bus line.This electrode array design, however, causes problems of couplingcapacitance and cross talk between the pixel electrode and the data busline.

Currently, two approaches to the disclination effect have beendeveloped, in which one is to keep a sufficient space between the pixelelectrode and the data bus line, and the other one is to employ a BM(black matrix) pattern for shielding the light leakage area. FIG. 1 is aplane view illustrating an electrode array of a conventional TFT-LCDdevice. FIG. 2 is a cross-section along line 1-1 of FIG. 1 illustratingthe space between the data bus line and the pixel electrode. A TFT-LCDdevice 10 comprises an upper glass substrate 12, a lower glass substrate14 and an LC layer 16 interposed therebetween. The upper glass substrate12 comprises a color filter (CF) layer 18, a black matrix (BM) layer 20and a common electrode layer 22. The lower glass substrate 14 comprisesa plurality of horizontally extended scanning bus lines 24 and aplurality of vertically extended data bus lines 26 which areperpendicularly arranged in a matrix form to define a plurality of pixelareas 28. Each of the pixel areas 28 comprises a TFT device 30, a pixelelectrode layer 32 and a pair of light-shielding layers 34.

First, a first metal layer is deposited and patterned as thelight-shielding layers 34 and the scanning bus lines 24, and then a gateinsulating layer 25 is deposited thereon. Next, a second metal layer isdeposited and patterned as the data bus lines 26, and then a passivationlayer 27 is deposited on the data bus lines 26 and the gate insulatinglayer 27. Next, a transparent conductive layer is deposited andpatterned as the pixel electrode layer 32. In addition, the BM layer 20overlap the TFT device 30, the light-leakage gap between the scanningbus line 24 and the periphery of the pixel electrode layer 32, and thelight-leakage gap between the data bus line 26 and the periphery of thepixel electrode layer 32. Also, the BM layer 20 may fully overlaps thelight-shielding layers 34.

In FIG. 1, the light-shielding layer 34 extends along the data bus line26 without connecting the scanning bus line 24 and is positioned in aspace between the data bus line 26 and the periphery of the pixelelectrode layer 32. Preferably, in the first pixel area 28I, the firstlight-shielding layer 34I is positioned in a first space between thefirst data bus line 26I and the periphery of the first pixel electrodelayer 32I, and the second light-shielding layer 34II is positioned in asecond space between the second data bus line 26II and the periphery ofthe first pixel electrode layer 32I. Also, the first-shielding layer 34Iis partially overlapped by the periphery of the first pixel electrodelayer 32I, and the second-shielding layer 34II is partially overlappedby the periphery of the first pixel electrode layer 32I.

In FIG. 2, using the first data bus line 26I as the criterion, a symbol“S₁” indicates a first space between the first data bus line 34I and theperiphery of the first pixel electrode layer 32I within the first pixelarea 28I, and a symbol “S₂” indicates a second space between the firstdata bus line 26I and the periphery of the second pixel electrode layer32I within the second pixel area 28II. According to a symmetric design,the first space S₁ is equal to the second space S₂, approximately 3.5μm. Also, a symbol “W₁” indicates a first overlapping width between theBM layer 20 and the first light-shielding layer 34I, and a symbol “W₂”indicates a second overlapping width between the BM layer 20 and thesecond light-shielding layer 34II. According to a symmetric design, thefirst overlapping width W₁ is equal to the second overlapping width W₂,approximately 6.0 μm.

In order to prevent the disclination effect, the conventional TFT-LCDdevice 10 employs the sufficient space S₁ or S₂ to minimize the couplingcapacitance and the electrical field between the data bus line 26 andthe periphery of the pixel electrode layer 32. The symmetric design rulefor the spaces S₁ and S₂, however, is ineffective because thedisclination level in the first space S₁ is different from that in thesecond space S₂ in accordance with a rubbing direction and the LCmolecule rotation. FIG. 3 is a plane view illustrating the disclinationlevel in the first space S₁ and the second space S₂. An arrow 36indicates a rubbing direction on an alignment film, an arrow 38indicates an LC rotating direction, and the character 40 indicates an LCmolecule. When an outer voltage is applied to the TFT-LCD device 10, theLC molecules 40 arise in a pretilt direction in accordance with therubbing direction 36. When a strong lateral electrical field between thepixel electrode layer 32 and the data bus line 26 is generated inreverse to the pretilt direction, the LC molecule 40 is oriented to thedirection of the lateral electrical field to reach a reverse tilt state,resulting in a disclination effect at a boundary between the normal tiltregion and the reverse tilt region. In particular when the rubbingdirection 36 is at a 45° angle to the X axis, the LC molecule 40Iadjacent to the first space S₁ always rotates to the reverse tilt state,thus the disclination effect adjacent to the first space S₁ is moreserious than that adjacent to the second space S₂. Based on thesymmetric design for the first space S₁ and the second space S₂, alarger space between the data bus line 26 and the periphery of the pixelelectrode layer 32 is required to solve the disclination effect found inthe first space S₁, but an accompanying problem of increased lightleakage occurs.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide an LCDdevice with a non-symmetric design for a space between a pixel electrodeand a data bus line in order to effectively prevent a disclinationeffect generated in a liquid crystal reverse region.

According to the object of the invention, a liquid crystal displaydevice comprises a first substrate, a second substrate and a liquidcrystal layer formed therebetween. A plurality of scanning bus lines anda plurality of data bus lines are perpendicularly arranged in a matrixform to define a plurality of pixel areas. A plurality of TFT devices isformed in the plurality of pixels, respectively. A plurality of pixelelectrode layers is formed in the plurality of pixels, respectively. Ineach pixel area, the pixel electrode layer is formed between a firstdata bus line and a second data bus line, and a first space between thefirst data bus line and the periphery of the pixel electrode layer isdifferent from a second space between the second data bus line and theperiphery of the pixel electrode layer.

DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawings,given by way of illustration only and thus not intended to be limitativeof the present invention.

FIG. 1 is a plane view illustrating an electrode array of a conventionalTFT-LCD device.

FIG. 2 is a cross-section along line 1-1 of FIG. 1 illustrating thespace between the data bus line and the pixel electrode.

FIG. 3 is a plane view illustrating the disclination level in the firstspace and the second space.

FIG. 4 is a plane view illustrating an electrode array of a TFT-LCDdevice according to the first embodiment of the present invention.

FIG. 5 is a cross-section along line 4-4 of FIG. 4 illustrating thenon-symmetric design for the data bus line and the pixel electrode.

FIG. 6 is a cross-section illustrating a non-symmetric design accordingto the second embodiment of the present invention.

FIG. 7 is a cross-section illustrating a non-symmetric design accordingto the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

First Embodiment

FIG. 4 is a plane view illustrating an electrode array of a TFT-LCDdevice according to the first embodiment of the present invention. FIG.5 is a cross-section along line 4-4 of FIG. 4 illustrating thenon-symmetric design for the data bus line and the pixel electrode.

A TFT-LCD device 50 comprises an upper substrate 52, a lower substrate54 and an LC layer 56 interposed therebetween. Preferably, the uppersubstrate 52 and the lower substrate 54 are glass substrates and opposedto each other in parallel. The upper substrate 52 comprises a colorfilter (CF) layer 58, an opaque layer 60, a common electrode layer 62and an upper alignment film 78I with a rubbing direction 76. Preferably,the opaque layer 60 is a black matrix (BM) layer.

The lower substrate 54 comprises a plurality of horizontally extendedscanning bus lines 64 and a plurality of vertically extended data buslines 66 which are perpendicularly arranged in a matrix form to define aplurality of pixel areas 68. Each of the pixel areas 68 comprises a TFTdevice 70, a pixel electrode layer 72 and a pair of light-shieldinglayers 74. In addition, the opaque layer 60 overlaps the TFT device 70,the light-leakage gap between the scanning bus line 64 and the peripheryof the pixel electrode layer 72, and the light-leakage gap between thedata bus line 66 and the periphery of the pixel electrode layer 72.Also, the opaque layer 60 may partially or fully overlap thelight-shielding layer 74 in accordance with the non-symmetric designrule of the first embodiment.

The fabrication method for an electrode array on the lower substrate 54is now described. First, a first metal layer is deposited and patternedas the light-shielding layers 74 and the scanning bus lines 64, and thena gate insulating layer 65 is deposited thereon. Next, a second metallayer is deposited and patterned as the data bus lines 66, and then apassivation layer 67 is deposited on the data bus lines 66 and the gateinsulating layer 65. Next, a transparent conductive layer (such as anITO layer) is deposited and patterned as the pixel electrode layer 72.Finally, a lower alignment film 78II with a rubbing direction 76 isformed on the pixel electrodes layer 72 and the passivation layer 67.

In FIG. 4, the light-shielding layer 74 extends along the data bus line66 without connecting the scanning bus line 64 and is positioned in aspace between the data bus line 66 and the periphery of the pixelelectrode layer 72. Preferably, in the first pixel area 68I, the firstlight-shielding layer 74I is positioned in a first space between thefirst data bus line 66I and the periphery of the first pixel electrodelayer 72I, and the second light-shielding layer 74II is positioned in asecond space between the second data bus line 66II and the periphery ofthe first pixel electrode layer 72I. Moreover, in accordance with thenon-symmetric design rule of the first embodiment, the first-shieldinglayer 74I or the second-shielding layer 74II may be partially overlappedby the periphery of the first pixel electrode layer 72I. Alternatively,the first-shielding layer 74I or the second-shielding layer 74II may notbe overlapped by the periphery of the first pixel electrode layer 72I.

In FIG. 5, using the first data bus line 66I as the criterion, a symbol“S₁” indicates a first space between the first data bus line 64I and theperiphery of the first pixel electrode layer 72I within the first pixelarea 68I, and a symbol “S₂” indicates a second space between the firstdata bus line 66I and the periphery of the second pixel electrode layer72II within the second pixel area 68II. According to a non-symmetricdesign for the TFT-LCD device 50, the first space S₁ of 3˜5 μm and thesecond space S₂ of 3˜5 μm satisfy the formula: S₁≠S₂. Especially when anincluded angle between the rubbing direction 76 and the data bus line 66is 40˜50 degrees, the first space S₁ between the first data bus line 66Iand the periphery of the first pixel electrode layer 72I is a liquidcrystal reverse region, and the second space S₂ between the first databus line 66I and the periphery of the second pixel electrode layer 72IIis a liquid crystal non-reverse region. Thus, the first space S₁ and thesecond space S₂ satisfy the formula: S₁>S₂, in which the first space S₁is preferably 4˜5 μm, and the second space S₂ is preferably 2˜3 μm.

Also, a symbol “W₁” indicates a first overlapping width between theopaque layer 60 and the first light-shielding layer 74I, and a symbol“W₂” indicates a second overlapping width between the opaque layer 60and the second light-shielding layer 74II. The first embodiment providesa symmetric design for the first overlapping width W₁ and the secondoverlapping width W₂, thus the first overlapping width W₁ of 5˜7 μm andthe second overlapping width W₂ of 5˜7 μm satisfy the formula: W₁=W₂.Preferably, the first overlapping width W₁ is preferably 6 μm, and thesecond overlapping width W₂ is 6 μm.

Compared with the conventional symmetric design rule for the spaces S₁and S₂, the present invention provides a non-symmetric design for thespaces S₁ and S₂ to effectively prevent the disclination effect from thedifferent disclination levels in the first space S₁ and the second spaceS₂. Particularly, the first space S₁ larger than the second space S₂ cansolve the serious disclination effect in the liquid crystal reverseregion without increasing light leakage by enlarging the first space S₁and the second space S₂ at the same time.

Second Embodiment

FIG. 6 is a cross-section illustrating a non-symmetric design accordingto the second embodiment of the present invention.

The elements in the second embodiment are substantially similar to thatof the first embodiment, with the similar portions omitted herein. Onedissimilar portion is a non-symmetric design for the first overlappingwidth W₁ and the second overlapping width W₂, and the other onedissimilar portion is a symmetric design for the first space S₁ and thesecond space S₂. According to a non-symmetric design for the firstoverlapping width W₁ and the second overlapping width W₂, the firstoverlapping width W₁ of 4˜8 μm and the second overlapping width W₂ of4˜8 μm satisfy the formula: W₁≠W₂. Especially when an included anglebetween the rubbing direction 76 and the data bus line 66 is 40˜50degrees, the first space S₁ is a liquid crystal reverse region, and thesecond space S₂ is a liquid crystal non-reverse region, thus the firstoverlapping width W₁ and the second overlapping width W₂ satisfy theformula: W₁>W₂, in which the first overlapping width W₁ is preferably6.5-7.5 μm and the second overlapping width W₂ is preferably 4.5˜5.5 μm.With regard to the symmetric design for the first space S₁ and thesecond space S₂, the first space S₁ of 3˜5 μm and the second space S₂ of3˜5 μm satisfy the formula: S₁=S₂. Preferably, the first space S₁ is 3.5μm, and the second space S₂ is 3.5 μm.

Compared with the conventional symmetric design rule for the overlappingwidths W₁ and W₂, the present invention provides a non-symmetric designfor the overlapping widths W₁ and W₂ to effectively prevent thedisclination effect from the different disclination levels in the firstoverlapping width W₁ and the second overlapping width W₂. Particularly,the first overlapping width W₁ larger than the second overlapping widthW₂ can solve the serious disclination effect in the liquid crystalreverse region without reducing an aperture ratio by enlarging theoverlapping widths W₁ and W₂ at the same time.

Third Embodiment

FIG. 7 is a cross-section illustrating a non-symmetric design accordingto the third embodiment of the present invention.

The elements in the third embodiment are substantially similar to thatof the first embodiment and the second embodiment, with the similarportions omitted herein. The third embodiment combines the non-symmetricdesign for the spaces S₁ and S₂ and the non-symmetric design for theoverlapping widths W₁ and W₂ to achieve the advantageous described inthe first embodiment and the second embodiment.

According to the non-symmetric design for the spacings S₁ and S₂, thefirst space S₁ of 3˜5 μm and the second space S₂ of 3˜5 μm satisfy theformula: S₁, S₂. Especially when an included angle between the rubbingdirection 76 and the data bus line 66 is 40˜50 degrees, the first spaceS₁ and the second space S₂ satisfy the formula: S₁>S₂, in which thefirst space S₁ is preferably 4˜5 μm and the second space S₂ ispreferably 2˜3 μm. According to the non-symmetric design for theoverlapping widths W₁ and W₂, the first overlapping width W₁ of 4˜8 μmand the second overlapping width W₂ of 4˜8 μcm satisfy the formula:W₁≠W₂. Especially when an included angle between the rubbing direction76 and the data bus line 66 is 40˜50 degrees, the first overlappingwidth W₁ and the second overlapping width W₂ satisfy the formula: W₁>W₂,in which the first overlapping width W₁ is preferably 6.5˜7.5 μm and thesecond overlapping width W₂ is preferably 4.5˜5.5 μm.

Compared with the conventional symmetric design rule for the spacings S₁and S₂ as well as the conventional symmetric design rule for theoverlapping widths W₁ and W₂, the present invention provides anon-symmetric design for the spacings S₁ and S₂ as well as anon-symmetric design for the overlapping widths W₁ and W₂ to effectivelyprevent the disclination effect from the different disclination levelsat opposite sides of the data bus line 66. This solves the seriousdisclination problem in the liquid crystal reverse region withoutdeteriorating light leakage and sacrificing aperture ratio.

While the invention has been described by way of example and in terms ofthe preferred embodiments, it is to be understood that the invention isnot limited to the disclosed embodiments. To the contrary, it isintended to cover various modifications and similar arrangements (aswould be apparent to those skilled in the art). Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements.

1. A liquid crystal display device, comprising: a first substrate and asecond substrate opposing each other; a liquid crystal layer formedbetween the first substrate and the second substrate; a plurality ofscanning bus lines and a plurality of data bus lines arranged in amatrix form to define a plurality of pixel areas; a plurality of TFTdevices formed in the plurality of pixels, respectively; and a pluralityof pixel electrode layers formed in the plurality of pixels,respectively; wherein, in each pixel area, the pixel electrode layer isformed between a first data bus line and a second data bus line; andwherein, in each pixel area, a first space between the first data busline and the periphery of the pixel electrode layer is different from asecond space between the second data bus line and the periphery of thepixel electrode layer.
 2. The liquid crystal display device as claimedin claim 1, further comprising: an alignment film of a rubbing directionin the plurality of pixels, respectively; wherein, when an includedangle between the rubbing direction and the data bus line is 40˜50degrees, the first space between the first data bus line and theperiphery of the pixel electrode layer is a liquid crystal reverseregion, and the second space between the second data bus line and theperiphery of the pixel electrode is a liquid crystal non-reverse region;and wherein, the first space adjacent to the liquid crystal reverseregion is larger than the second space adjacent to the liquid crystalnon-reverse region.
 3. The liquid crystal display as claimed in claim 2,wherein the first space is 4˜5 μm and the second space is 2˜3 μm.
 4. Theliquid crystal display device as claimed in claim 1, further comprising:an opaque layer overlapping the first data bus line, the second data busline, the first space and the second space; and a plurality oflight-shielding layers formed in the plurality of pixel areas,respectively; wherein, in each pixel area, a first light-shielding layeris formed between the first data bus line and the periphery of the pixelelectrode layer; and wherein, in each pixel area, a secondlight-shielding layer is formed between the second data bus line and theperiphery of the pixel electrode layer; and wherein, a first overlappingwidth is defined between the opaque layer and the first light-shieldinglayer, and a second overlapping width is defined between the opaquelayer and the second light-shielding layer.
 5. The liquid crystaldisplay as claimed in claim 4, wherein the first overlapping width isequal to the second overlapping width.
 6. The liquid crystal display asclaimed in claim 4, wherein the first overlapping width is differentfrom the second overlapping width.
 7. The liquid crystal display deviceas claimed in claim 6, further comprising: an alignment film of arubbing direction formed in the plurality of pixels, respectively;wherein, when an included angle between the rubbing direction and thedata bus line is 40-50 degrees, the first space between the first databus line and the periphery of the pixel electrode layer is a liquidcrystal reverse region, and the second space between the second data busline and the periphery of the pixel electrode is a liquid crystalnon-reverse region; and wherein, the first overlapping width adjacent tothe liquid crystal reverse region is larger than the second overlappingwidth adjacent to the liquid crystal non-reverse region.
 8. The liquidcrystal display as claimed in claim 7, wherein the first overlappingwidth is 6.5˜7.5 μm and the second overlapping width is 4.5˜5.5 μm. 9.The liquid crystal display device as claimed in claim 4, wherein thesecond substrate further comprises: a gate insulating layer formedoverlying the second substrate and covering the scanning bus lines andthe light-shielding layers, in which the data bus lines are formedoverlying the gate insulating layer; and a passivation layer formedoverlying the gate insulating layer and covering the data bus lines, inwhich the pixel electrode layers are formed overlying the passivationlayer.
 10. The liquid crystal display as claimed in claim 1, wherein thefirst substrate further comprises a color filter layer and a commonelectrode layer.
 11. A liquid crystal display device, comprising: afirst substrate and a second substrate opposing to each other; a liquidcrystal layer formed between the first substrate and the secondsubstrate; a plurality of scanning bus lines and a plurality of data buslines arranged in a matrix form to define a plurality of pixel areas; aplurality of TFT devices formed in the plurality of pixels,respectively; a plurality of pixel electrode layers formed in theplurality of pixels, respectively; a plurality of light-shielding layersformed in the plurality of pixel areas overlying the second substrate,respectively; and an opaque layer formed overlying the first substrate;wherein, in each pixel area, the pixel electrode layer is formed betweena first data bus line and a second data bus line, in which a firstdistance is kept between the first data bus line and the periphery ofthe pixel electrode layer, and a second space is kept between the seconddata bus line and the periphery of the pixel electrode layer; wherein,in each pixel area, a first light-shielding layer is formed between thefirst data bus line and the periphery of the pixel electrode layer, anda second light-shielding layer is formed between the second data busline and the periphery of the pixel electrode layer; wherein, the opaquelayer overlaps the first data bus line, the second data bus line, thefirst space and the second space; wherein, in each pixel area, a firstoverlapping width between the opaque layer and the first light-shieldinglayer is different from a second overlapping width between the opaquelayer and the second light-shielding layer.
 12. The liquid crystaldisplay device as claimed in claim 11, further comprising: an alignmentfilm of a rubbing direction formed in the plurality of pixels,respectively; wherein, when an included angle between the rubbingdirection and the data bus line is 40˜50 degrees, the first spacebetween the first data bus line and the periphery of the pixel electrodelayer is a liquid crystal reverse region, and the second space betweenthe second data bus line and the periphery of the pixel electrode is aliquid crystal non-reverse region; and wherein, the first overlappingwidth adjacent to the liquid crystal reverse region is larger than thesecond overlapping width adjacent to the liquid crystal non-reverseregion.
 13. The liquid crystal display as claimed in claim 12, whereinthe first overlapping width is 6.5˜7.5 μm and the second overlappingwidth is 4.5˜5.5 μm.
 14. The liquid crystal display as claimed in claim11, wherein the first space is equal to the second space.
 15. The liquidcrystal display as claimed in claim 11, wherein the first space isdifferent from the second space.
 16. The liquid crystal display deviceas claimed in claim 15, further comprising: an alignment film of arubbing direction formed in the plurality of pixels, respectively;wherein, when an included angle between the rubbing direction and thedata bus line is 40˜50 degrees, the first space between the first databus line and the periphery of the pixel electrode layer is a liquidcrystal reverse region, and the second space between the second data busline and the periphery of the pixel electrode is a liquid crystalnon-reverse region; and wherein, the first space adjacent to the liquidcrystal reverse region is larger than the second space adjacent to theliquid crystal non-reverse region.
 17. The liquid crystal display asclaimed in claim 16, wherein the first overlapping width is 4˜5 μm andthe second overlapping width is 2˜3 μm.
 18. The liquid crystal displaydevice as claimed in claim 11, wherein the second substrate furthercomprises: a gate insulating layer formed overlying the second substrateand covering the scanning bus lines and the light-shielding layers, inwhich the data bus lines are formed overlying the gate insulating layer;and a passivation layer formed overlying the gate insulating layer andcovering the data bus lines, in which the pixel electrode layers areformed overlying the passivation layer.
 19. The liquid crystal displayas claimed in claim 11, wherein the first substrate further comprises acolor filter layer and a common electrode layer.
 20. A fabricationmethod for a liquid crystal display device, comprising steps of:providing a first substrate; forming a plurality of scanning bus linesand a plurality of light-shielding layers overlying the first substrate;forming a gate insulating layer overlying the first substrate to coverthe scanning bus lines and the light-shielding layers; forming aplurality of data bus lines overlying the gate insulating layer, inwhich the data bus lines and the scanning bus lines are arranged in amatrix form to define a plurality of pixel areas; forming a plurality ofTFT devices in the plurality of pixels, respectively; and forming aplurality of pixel electrode layers overlying the passivation layer inthe plurality of pixels, respectively; wherein, in each pixel area, thepixel electrode layer is formed between a first data bus line and asecond data bus line; and wherein, in each pixel area, a first spacebetween the first data bus line and the periphery of the pixel electrodelayer is different from a second space between the second data bus lineand the periphery of the pixel electrode layer.
 21. The fabricationmethod for a liquid crystal display device as claimed in claim 20,further comprising a step of: forming an alignment film of a rubbingdirection overlying the pixel electrode and the passivation layer;wherein, when an included angle between the rubbing direction and thedata bus line is 40˜50 degrees, the first space between the first databus line and the periphery of the pixel electrode layer is a liquidcrystal reverse region, and the second space between the second data busline and the periphery of the pixel electrode is a liquid crystalnon-reverse region; and wherein, the first space adjacent to the liquidcrystal reverse region is larger than the second space adjacent to theliquid crystal non-reverse region.
 22. The fabrication method for aliquid crystal display device as claimed in claim 21, wherein the firstspace is 4˜5 μm and the second space is 2˜3 μm.
 23. The fabricationmethod for a liquid crystal display device as claimed in claim 20,further comprising steps: providing a second substrate opposing to thefirst substrate; and forming an opaque layer overlying the secondsubstrate, in which the opaque layer overlaps the first data bus line,the second data bus line, the first space and the second space; wherein,in each pixel area, the first light-shielding layer is formed betweenthe first data bus line and the periphery of the pixel electrode layer;wherein, in each pixel area, the second light-shielding layer is formedbetween the second data bus line and the periphery of the pixelelectrode layer; and wherein, a first overlapping width is definedbetween the opaque layer and the first light-shielding layer, and asecond overlapping width is defined between the opaque layer and thesecond light-shielding layer.
 24. The fabrication method for a liquidcrystal display as claimed in claim 23, wherein the first overlappingwidth is equal to the second overlapping width.
 25. The fabricationmethod for a liquid crystal display as claimed in claim 23, wherein thefirst overlapping width is different from the second overlapping width.26. The fabrication method for a liquid crystal display as claimed inclaim 25, further comprising a step of: forming an alignment film of arubbing direction overlying the pixel electrode layer and thepassivation layer; wherein, when an included angle between the rubbingdirection and the data bus line is 40˜50 degrees, the first spacebetween the first data bus line and the periphery of the pixel electrodelayer is a liquid crystal reverse region, and the second space betweenthe second data bus line and the periphery of the pixel electrode is aliquid crystal non-reverse region; and wherein, the first overlappingwidth adjacent to the liquid crystal reverse region is larger than thesecond overlapping width adjacent to the liquid crystal non-reverseregion.
 27. The fabrication method for a liquid crystal display asclaimed in claim 26, wherein the first overlapping width is 6.5˜7.5 μmand the second overlapping width is 4.5˜5.5 μm.
 28. The fabricationmethod for a liquid crystal display as claimed in claim 23, furthercomprising steps of: forming a color filter layer overlying the secondsubstrate; forming a common electrode layer overlying the color filterlayer and the opaque layer; and forming an alignment layer overlying thecommon electrode layer.
 29. The fabrication method for a liquid crystaldisplay as claimed in claim 23, further comprising a step of forming aliquid crystal layer between the first substrate and the secondsubstrate.
 30. A fabrication method for a liquid crystal display device,comprising steps of: providing a first substrate; forming a plurality ofscanning bus lines and a plurality of light-shielding layers overlyingthe first substrate; forming a gate insulating layer overlying the firstsubstrate to cover the scanning bus lines and the light-shieldinglayers; forming a plurality of data bus lines overlying the gateinsulating layer, in which the data bus lines and the scanning bus linesare arranged in a matrix form to define a plurality of pixel areas;forming a plurality of TFT devices in the plurality of pixels,respectively; forming a plurality of pixel electrode layers overlyingthe passivation layer in the plurality of pixels, respectively;providing a second substrate opposing to the first substrate; andforming an opaque layer overlying the second substrate; wherein, in eachpixel area, the pixel electrode layer is formed between a first data busline and a second data bus line; and wherein, in each pixel area, afirst space is kept between the first data bus line and the periphery ofthe pixel electrode layer, and a second space is kept between the seconddata bus line and the periphery of the pixel electrode layer; andwherein, in each pixel area, a first light-shielding layer is formedbetween the first data bus line and the periphery of the pixel electrodelayer, and a second light-shielding layer is formed between the seconddata bus line and the periphery of the pixel electrode layer; andwherein, the opaque layer overlaps the first data bus line, the seconddata bus line, the first space and the second space; and wherein, afirst overlapping width between the opaque layer and the firstlight-shielding layer is different from a second overlapping widthbetween the opaque layer and the second light-shielding layer.
 31. Thefabrication method for a liquid crystal display device as claimed inclaim 30, further comprising a step of: forming an alignment film of arubbing direction overlying the pixel electrode and the passivationlayer; wherein, when an included angle between the rubbing direction andthe data bus line is 40˜50 degrees, the first space between the firstdata bus line and the periphery of the pixel electrode layer is a liquidcrystal reverse region, and the second space between the second data busline and the periphery of the pixel electrode is a liquid crystalnon-reverse region; and wherein, the first overlapping width adjacent tothe liquid crystal reverse region is larger than the second overlappingwidth adjacent to the liquid crystal non-reverse region.
 32. Thefabrication method for a liquid crystal display device as claimed inclaim 31, wherein the first space is 6.5˜7.5 μm and the second space is4.5˜5.5 μm.
 33. The fabrication method for a liquid crystal display asclaimed in claim 30, wherein the first space is equal to the secondspace.
 34. The fabrication method for a liquid crystal display asclaimed in claim 30, wherein the first space is different from thesecond space.
 35. The fabrication method for a liquid crystal display asclaimed in claim 34, further comprising a step of: forming an alignmentfilm of a rubbing direction overlying the pixel electrode layer and thepassivation layer; wherein, when an included angle between the rubbingdirection and the data bus line is 40˜50 degrees, the first spacebetween the first data bus line and the periphery of the pixel electrodelayer is a liquid crystal reverse region, and the second space betweenthe second data bus line and the periphery of the pixel electrode is aliquid crystal non-reverse region; and wherein, the first space adjacentto the liquid crystal reverse region is larger than the second spaceadjacent to the liquid crystal non-reverse region.
 36. The fabricationmethod for a liquid crystal display as claimed in claim 35, wherein thefirst overlapping width is 4˜5 μm and the second overlapping width is2˜3 μm.
 37. The fabrication method for a liquid crystal display asclaimed in claim 30, further comprising steps of: forming a color filterlayer overlying the second substrate; forming a common electrode layeroverlying the color filter layer and the opaque layer; and forming analignment layer overlying the common electrode layer.
 38. Thefabrication method for a liquid crystal display as claimed in claim 30,further comprising a step of forming a liquid crystal layer between thefirst substrate and the second substrate.